1. Field of the Invention
The present invention relates to an image processing apparatus, a controlling method, and a program for controlling a fixing temperature when a toner image is fixed onto a recording paper.
2. Description of the Related Art
In an image forming apparatus that thermally fixes a toner image formed by electrophotography onto a recording paper, normally, the fixing temperature of a fixing unit is determined according to the amount per unit area of coloring material placed on a recording paper. For example, the maximum value of the amount of coloring material per unit area is determined in advance and the fixing temperature for fixing an image is adjusted so that the amount of coloring material per unit area is smaller than or equal to the maximum value.
A full-color copying machine forms an image by superimposing a plurality of color materials such as YMCK (yellow, magenta, cyan, and black), so that the amount of color materials (hereinafter referred to as the amount of tonner) placed on a recording paper tends to increase. Therefore, the thermal capacity of a fixing roller increases. In this case, just after powering on of the machine or just after the sleep state of the machine ends, the temperature of the fixing roller is lower than a predetermined fixing temperature, so that it is necessary to warm the fixing roller up to the predetermined fixing temperature. Therefore, there is a problem that there is a waiting time until printing starts. When outputting an image where the amount of toner is significantly lower than the assumed maximum value of the amount of toner, for example, when outputting an image in a monochrome mode using only a color material of color K, excessive heating is performed, depending on an image to be output, so that there are problems, such as useless power consumption and curling of transfer paper.
To solve the above problems, as a related art, Japanese Patent Laid-Open No. H10-039673 (1998) discloses a technique for correcting the fixing temperature according to the image contents of images to be printed, such as characters and photos on one page.